Sealing of cartons



June 15, 194 H. H. BEASLEY SEALING OF CARTONS Filed Jan. 27, 1941 4Sheets-Sheet l SEALING 0F CARTONS 4 4 Sheets-Sheet 2 Filed 'Jan. 27,1941 June 15, 1943. H. H. BEASLEY SEALING OF CARTONS Filed Jan. 27, 1941Sheets-Sheet 4 [206% Ef/Bemley per iAfif r/zega Patented June 15, 1943SEALING F CARTONS Harold Holmyard Bea le i Eng y, Ashton Gate, Bristol,land Application January'zi, 1941, Serial No. 876,207

, In Great Britain February 6, 1940 9 Claims. (Ci. 93-6) This inventionrelates to the sealing 'of cartons, and more particularly cartons of thetype which are impregnated or coated with a sealing substance which canbe rendered tacky by heat application, such as for example cartonscomposed of cardboard or stout paper impregnated or coated with wax torender them waterproof, the sealing being effected by softening the waxin proximity to the mouth and then pinching opposed sides of the mouthtogether. A form of carton to which the present invention is mostappropriately applicable is that which when closed has a wedge-shapedupper part obtained by two opposed inverted Y-shaped folds which enablestwo sides to be converged or pinched together and united at the mouth byheat sealing. One of such sides can have a flap which can be folded overthe other side to form a positive closure and a treble thickness at themouth. Cartons of this type can have a cylindrical or rectangular bodypart with a wedge-like upper part, and in practice it is advantageous toadopt the rectangular form as it can be stacked and maniP- ulated quiteconveniently. .The heat sealing of cartons of this character haspreviously been proposed by passing them from a heating stage intoacombined cooling and pinching stage so that in each stage a number ofcartons are bein treated simultaneously. In one such heretofore proposedmethod the heating and the combined pinching and cooling is effected bypinching the cartons between the opposed parallel tracks of a pair ofendless bands for each stage, the cartons passing from between one pairof bands to the other pair of bands in succession in a continuousmanner. tion is to obtain a highly positive treatment of each cartonindividually over a protracted period by a method which ensures a rapidrate of supply of cartons to be sealed andanother object of thisinvention-is to provide mechanisms for sealing cartons in whichsimultaneously a number of cartons are receiving individuallydistinctive operations appropriate to folding, heating and sealing, sothat cartons'can be fed successively at a relatively high rate to andfrom the mechanism. According to this invention a method of heat'sealing cartons in which the waxy or like coating or impregnant of thecartons is softened by heat treatment to obtain tacky areas which arepinched together and cooled to re-harden the tacky areas, ischaracterised in that each carton is passed through-the heating stageand thereafter the cooling and pinching stage by a plurality ofintermittent movements in each stage and that during each -stationaryperiod a heated carton is automatically displaced from the heating stageinto the cooling and pinching stage simultaneously with the feeding of anon-heattreated carton into the heating stage, each carton beingcontinuously treated in each stage during a succession of stationary andmoving periods. I

In a preferred form of this invention, a carton sealing machine hasthree treatment stages, i. e. initially or partially closing, heatsoftening of the adhesive medium and then sealing. Combined with thesestages is an automatic feeding or the unsealed cartons from a conveyorto the initially or partially closing stage, and means for automaticallydischarging the sealed cartons on to a collecting conveyor. a

In carrying one form of the invention into practice a carton sealingmachine suitable for sealing cartons of the type adapted when closed tohave the said wedge-like upper parts, com- The chief object of thepresent invenprises a number of rotary carriers each having associatedtherewith distinctive carton treatin means, a conveyor for deliveringopen cartons successively to one of the carriers, and another conveyorfor conveying away the sealed cartons, the carrier which receives theopen cartons having hoods provided therewith adapted to be engaged withthe open upper end of the cartons to fold them into a closed orwedge-like form, means transferring the cartons from such rotary carrierto another of the rotary carriers provided withheating means forsoftening the wax or i other sealing medium of the cartons, meanstransferring the cartons from this heating stage to a further one of thesaid carriers provided with means for pinching together and cooling themouth parts of the cartons to eifect a final sealing operation, andmeans discharging the cartons successively from the latter carrier to adischarge conveyor, the arrangement being that the carriers are rotatedsimultaneously in an intermittent manner and that all of the saidtransferring operations and also the folding of the carton mouths by thehoods are effected simultaneously during the stationary periods of thecarriers.

The said transferring operations can be effected by a number of pushers,the pushers being carried by slides operated-simultaneously by a commonoperating member through the medium of cables, the said hoods which foldthe carton tops being arranged equidistantly apart above the appropriatecarrier and manipulated successively by a reciprocating member operatedfrom a rotary member such as e. g., a cam. Suitable means is provided toscreen the predominating portion of each carton from the heating means,particularly when, as would generally be the case, the cartons are ofthe wax impregnated or coated class. However, the invention isapplicable to cartons which have only a narrow section coated witha-substance capable of being rendered adhesive by heat treatment solelyfor sealing purposes.

In order that this invention may be clearly understood and readilycarried into effect drawings are appended hereto somewhatdiagrammatically illustrating embodiment thereof, and wherein:

Fig. 1 is a side elevation view partly in section.

Fig. 2 is a plan view with the overhead framework removed.

Fig. 3 is a side elevation showing the means for operating the pushermembers.

Fig. 4 is a plan view of Fig. 3.

Fig. 5 is a broken sectional elevation view to a larger scale showingthe carton top heating and pinching appliances.

Fig. 6 is a detail elevational view to. a larger scale showing one ofthe hoods engaged with the top of a carton.

Fig. '7 is a side elevation view of Fig. 6 and showing the ingress andegress stages of a carton relatively to a hood.

Fig. 8 is a broken diagrammatic plan view showing the means foroperating the members which pinch and seal the cartons.

Fig. 9 shows in broken perspective a carton after its top has beenclosed by the machine, and

Fig. 10 is a. detail sectional end elevation View of one of the heatingdevices with the upper part of a carton shown in broken lines.

Referring to the drawings, in the appropriate parts thereof the cartonsare.indicated by the reference numeral I, and the conveyer which carriesthe open cartons to the machine is indicated by the reference numeral 2,the discharge conveyer being indicated by the reference numeral 3. Themachine frame is indicated by the reference numeral 4. Upon this frameare mounted three rotary carriers 5, 6 and I which respectively carrythe means appropriate to (1) folding the tops of the cartons, (2)heating such tops to soften the wax in proximity to the mouths, and (3)pinching and cooling the mouths to seal them.

By reference to Fig. 2 it will be seen that the carriers 5 and 6 arerotated anti-clockwise and the carrier 1 clockwise. This rotation isintermittent, the intermittency being effected by a geneva cross rotarymember 3 driven by a primary wheel 9 carrying the pin 9:: to engage theradial slots 8a of the member 8. The member 8 is fixed on a verticalshaft 10 which carries a gear wheel ll meshing with a gear wheel i2driving the carrier 5 and with a gear wheel 5a driving the carrier 6,the gear wheel 6a meshing with a like gear wheel la driving the carrier1 (see Fig. 5) thus ensuring simultaneous movements of the rotarycarriers 5, 6 and I.

- Each movement of 90 of the carrier 5 brings opposite the discharge endof the feeding conveyor 2 a hood 13, there being four of these hoods. Apusher bar It operated by means hereinafter described is, during thestationary periods of the carrier 5, moved across the discharge end ofthe conveyor 2 to displace a carton onto the carrier 5 immediatelybeneath the adjacent hood. This hood is then urged downwardly apredetermined amount and in doing so it folds in the open upper end ofthe carton to 213; closed condition as more clearly shown in Each hoodI3 is an inverted V section member, the two limbs Ba and l3b beingjoined at the inner end by an endplate I30 the other end being open sothat at the appropriate stage the carton may be ejected from the carrier5 on to the carrier 6, this latter stage being that diametricallyopposed to the receiving stage (opposite pusher bar. I4) and thedisplacement of the carton from the carrier 5 being eflected by a pusherbar l5 (see Figs. 3 and 4) which moves in unison with the pusher bar Itso that there is a simultaneous loading and discharging of cartons ateach'stationary period of the carrier 5.

The sliding movement of each'carton beneath a hood l3 on to the carrier6 can be utilized for the purpose of folding a flap la carried by oneside of each carton flush against the other side of the carton month.When a hood i3 descends over a carton the flap la is engaged by ahorizontal plate l3d of the hood, this plate projecting uni-laterallyfrom a short vertical extension l3e of the limb I31), the upper edge ofthe other limb i3a being spaced below the plate 13d (see Fig. 6) toleave the filap in free to engage the plate l3d, at which stage thecarton is nearer the axis of the carrier 5 than the periphery of saidcarrier, i. e., under the inner end of the appropriate hood. When thecarton is pushed from under the hood its flap la. is folded inwards bythe plate l3d which plate as it approaches its outer end is bent intothe vertical plane, this bend being indicated at I3! in Fig. 7.

Supported by a centre column IS on the carrier 6 is an overhead heatingchamber I! the base plate Ha of which has formed on its lower face aplurality of radiating narrow channel section bars !8 each shaped toclosely engage over a closed upper part of /a carton. At each stationaryperiod of the carriers 5 and 6 one of these channel sections bars is inalignment with the apex of a hood I3 so that a carton is pressed by thepusher bar l5 on to the carrierii and with its peak, or flap closedmouth, engaged in a channel section bar or between a narrowly spacedpair of bars I8 as shown in Fig. 10. These bars I8 are heated by anysuitable means, such as e. g. electric heating elements Me, thetemperature of the bars, if desired, being regulated by a thermostat 2o.

There are more pairs of heater bars l8 than hoods l3, e. g. twelve tofour as shown in Fig. 2,

and the gear ratio of the gear wheels Ii, l2, Ga

and 1a transmitting the drive from the shaft ll to the carrier 6 is suchas to ensure the requisite reduction in angle of movement of the carrier6 relatively to the carrier 5. This enables each carton to be subjectedto the influence of heat over a sufficiently lengthy period toadequately soften the wax at the mouth and flap of the carton. Suitablescreens or partitions i9 may be provided on the carrier 6 to screen thebodies of the cartons from heat radiating from the bars i8 so that onlythe mouth parts of the cartons ar softened.

As great an angle of movement as reasonably possible of the carrier 6 isutilised for obtaining the efiective carton heating period, and in theexample illustrated (Fig. 2) this angle is 270, the carton dischargepoint having a pusher bar 2| (see Figs. 3 and 4) which operates inunison with the beforesaid pusher bars l4 and I5 and tions it isprovided with .a plurality of radiating pinching devices indicatedgenerally by the reference numeral 22 in Fig. 2. These pinching devicesand the gear driving the carrier are arranged so that at each stationaryperiod a heating bar i8 is aligned with a pinching device 22, thisbeing'elear by reference to Fig. 2, the pusher bar 2i reciprocatingalong this lineof alignment. Another pusher bar 50 operating in adirection at frame 4 to take the arms carrying the pusher appropriatestages.

right angles to the pusher bar 2i, pushes the cartons singly from thecarrier end of the conveyor 3.

To more clearly indicate the relative positions of the pusher bars i4,15, H and 5B, and the carriers 5, 6 and i, the outer tracks of movementof these carriers are indicated in Fig. 4 by the broken circles 5 6 and1 The hoods i3 reciprocate vertically and when each hood is in theloading position (opposite pusher bar id) it israised to enable a cartonto pass easily thereunder. This raising can be effected byany suitablemechanism, such as e. g. a ring 23 with a cam 23a adapted to engagesuccessively the lower ends of four vertically slidable arms 24 eachattached at its upper end to the inner end of one of the hOOds l3, thesearms as being slidably supported in suitable fixed guides indicateddiagrammatically by the reference numeral 25 in Fig. 1. The lower endsof these arms 24 carry rollers which in the lowered position of thehoods rest upon the machined face of the l on to the receiving ring 23frame and travel in a: circular path. This raising and lowering of thehoods only occupies a Each such device comprises a fixed bar 5| and a,

presser bar 52 arranged radially on the base of the cooling chamber 58carried above the carrier I on the shaft 5! which carries gear wheel Iand the carrier i, each presser bar 52 being slightly spaced therefromand provided with means tomove it towards and away from the bar 5i atthe A cover plate 51 closes the top of the cooling chamber 58.

The closed or pinching stage of each pair of bars 5i and 52 occupiesnearly the whole of the travel between the pusher bars 2i and 50, i. e.nearly 270 so that there is a protracted sealing period as compared withthe relatively short loading intervals appropriate to the delivery ofopen cartons from the conveyor 2 into the machine.

Each presser bar 52 can be actuated by a cam or eccentric 53 on thelower end of a spindle 56, the upper end of which carries a V-shapedlever 55 one end of which has anchored to it one end of a coiled tensionspring 53 which applies the sealing pressure to the presser bar 52 andeach such spring is anchored at its other end to the top'o'f one of thespindles 5 as shown in Fig. 2. The other end of this lever 55 carries aroller 59 adapted when the appropriate presser bar 52 reaches theunloading position opposite the pusher bar'50 to engage one end of afixed cam plate 60 which extends to a point Just beyond the loadingstage opposite the pusher bar 2 i. By

a this means the presser bars 52 are held away from short time-andoccurs whilst the carrier 5 is stationary. The descent of the hoods isassisted y springs 28. v

The pusher bars l4, I5, 2! and 50 can be operated from a common cam 33(see Figs. 3 and 4) engaged at its perimeter by a lever 34 to one end ofwhich are anchored a pairof cables 35 and 36 which are passed overpulleys 35a and 36a respectively. The cable 35 is guided over a furtherpulley 35b and anchored to a sleeve 31 slidable on a fixed guide rod 38,a strong coiled tension spring 39 yieldingly opposing the pull of thecable 35 and maintaining the cable constantly under tension. The sleeve31 carries a cranked arm 40 which has adjustably fixedto its free endthe pusher bar l4.

The other cable 36 operates the pusher bars i5, 2| and 50. The pusherbar 2i is carried by an arm 4| attached by a cranked extension 4la'to asleeve 42 slidable along a fixedguide rod 43, and the pusher bar 50 iscarriedby an arm 44 fixed to a sleeve 45 slidable at one end on a guiderod 45 and suitable guided at its other end. The cable 36 is passed overpulleys 36b, 36c'and 36d and then threaded through and secured to an arm42a fixed to the sleeve 42 of the pusher bar 2|; and is carried beyondthis; arm 42a over a pulley 36c and then anchored to the sleeve 45. Thepusher bar i5 is also affixed to the sleeve 45. A strong coiled tensionspring 41 yieldingly opposes the pull of the cable.36 and returns thepusher bars l5, 2i and so to their retracted posibe provided to take upany slack that might arise in the the fixed bars against the influenceof their springs 55 for just over 90 of the travel of the carrier 1 toenable loading and unloading of the cartons to be eflectedin connectionwith the carrier 1. It is of course understood-that the numbers ofsprings 56 with their levers 55 correspond in number to the number ofpinching devices.

Any suitable cooling medium may be located in or circulated through thecooling chamber 58, 7

this chamber being supported by the shaft which carries the rotarycarrier 1.

It will be apparent from the foregoing that a high rate of supply ofopen cartons to and fromthe machine can be obtained with a relativelyprotracted period for' adequately sealing the cartons, means to depressthe hoods to fold the cartons into a closed or wedge-like form, means toengage and push the cartons from under such hoods to another of therotary carriers, heating means located abovesald latter rotary carrierfor 35 and 38. Slots 48 are provided in the machine softening the wax orother sealingjmedium of the cartons, means to engage and push the upperparts of the cartons from this heating means to a further one ofthe-said carriers, pinching devices above said further one of saidcarriers for pinching together the mouthparts of the cartons to effect afinal sealing operation, means discharging the cartons successively fromthe latter carrier to said discharge conveyor, means rotating thecarriers simultaneously in an intermittent manner and mechanism foroperating all of the said carton pushing and discharging meanssimultaneously during the stationary periods of the carriers.

2. In a machine for heat sealing cartons having a carton top closingmechanism and heating and pinching mechanisms, said top closingmechanism comprising a set of hoods, an inverted V- shaped carton topengaging part on each hood adapted to impart a wedge-like shape to eachcarton top, means to feed the cartons under the hoods, means to raiseand lower the hoods, and flap closing means on each hood comprising anabutment projecting laterally beyond the upper part of one limb of eachinverted V-shaped hood part over the other limb and bent throughsubstantially 90 at one end, through which end the cartons aredischarged from the hood into the heating mechanism.

3. In a machine for heat sealing cartons, an initial carton top closingmechanism, a carton top heating device and a carton top pinching andcooling appliance, three rotary carriers carrying said mechanism,heating device and carton top pinching and cooling appliance eachadapted to carry a plurality of cartons simultaneously, means to feedthe cartons singly from one carrier to another, said means to pinch andcool the carton tops comprising a top member disposed above and carriedby the rotary carrier of the pinching and cooling appliance, a pluralityof radiating pairs of pinch bars carried by the base of said top member,means to automatically pinch together each pair of said pairs of barsafter feeding between them a carton, a carton collecting device, meansto successively separate each pair of the pairs of pinch bars when theappropriate carrier locates a carton opposite said collecting device,and means automatically pushing the cartons in succession from saidpinch bars on to said collecting device.

4. In a machine for heat sealing cartons a number of rotating carrierseach adapted to support a plurality of cartons simultaneously and havingassociated therewith distinctive carton treating means and comprising afirst rotary carrier adapted to receive singly successively opencartons, means with said carrier automatically folding the tops of thecartons to a closed condition, a second rotary carrier, meansautomatically transferring the closed top cartons successively to thesecond rotary carrier, heating means with said latter carrier to renderthe tops of the cartons adhesive, a third rotary carrier, pinchingdevices on said third carrier means adapted to automatically transferthe cartons singly successively fromthe second carrier to the pinchingdevices on the third rotary carrier to pinch the adhesive carton topsand cool them to effect a sealing operation, and means automaticallydelivering the sealed cartons in succession from the latter carrier,gearing connecting the rotary carriers in a train and impartingintermittent simultaneous rotation to the carriers, said meansautomatically transferring the cartons from one carrier to anothercomprising pusher members operating in unison during the station.- aryperiods of the carriers to engage and push cartons singly from eachcarrier so that a number of cartons are transferred simultaneouslyacross the diiferent carriers and'a plurality of cartons are heattreated and a plurality pinched and cooled simultaneously.

5. In a machine for heat sealing cartons a number of carton supportingcarriers, and carton supply and discharging conveyors to supply car tonsto and remove them from the machine, means with each of said carriersfor applying an operation appropriate to a sealing treatment to a numberof cartons simultaneously for each delivery of an unsealed carton to themachine, a set of carton receivers on each carrier, means to traversethe carriers intermittently in unison, and means automatically operatingduring the stationary periods of the carriers to feed a carton from thesupply conveyor to one of the carriers and to feed a sealed carton fromanother of the carriers.to the conveyor removing cartons from themachine.

6. A machine for heat sealing cartons comprising a movable carrieradapted to receive singly successively open cartons, carton top foldingmeans located above said carrier and adapted to engage and automaticallyfold the tops of the cartons on the carrier to a closed condition, asecond movable carrier, means automatically transferring the closed topcartons successively from the first to the second movable carrier,heating members supported above said latter carrier and adapted toreceive the tops of the cartons to render them adhesive by heat, a thirdmovable carrier, pinching devices on said latter carrier adapted topinch the carton tops, means adapted to automatically transfer thecartons singly successively to said third carrier and pinching devicesfrom the said second carrier, means automatically discharging the sealedcartons in succession from the said third carrier, and meansautomatically opening the pinching devices when they receive and arefreed of cartons and automatically pinching them on to the cartonsbetween such receiving and discharging operations.

7. In a machine for heat sealing cartons a number of rotating carrierseach adapted to support a plurality of cartons simultaneously and havingassociated therewith distinctive carton treating means and comprising afirst rotary carrier adapted to receive singly successively opencartons, means on said first carrier automatically folding the tops ofthe cartons to a closed condition, a second rotary carrier, pushermembers automatically transferring the closed top cartons successivelyto the second rotary carrier, heated guides to receive the carton topson said latter carrier to render the tops of the cartons adhesive byheat, a third rotary carrier, carton top engaging and pinching devicescarried by the said third carrier and means opening and closing saiddevices relative to said third carrier, means adapted to automaticallypush the cartons singly successively to the said pinching devices, andmeans automatically delivering the sealed cartons in succession from thelatter carrier, said means folding the tops of the cartons to a closedcondition comprising inverted substantially V-shaped hoods and means tolower each hood over a carton so as to fold to a wedge-like form the topof the carton and to raise the hood to receive a new carton.

8. In a machine for heat sealing cartons a plurality of distinctivetreatment apparatus operating in unison, comprising a set of hoods, eachhood having an inverted V-shaped carton top engaging portion, means toraise and lower the hoods, traversing means operating relative to thetreatment apparatus to traverse the open cartons the hoods when thehoods are raised, further traversing means operating simui taneouslywith the beioresaid traversing means to initial carton top closingmechanism and heatingand pinching mechanisms rotary carriers, a set ofhoods incorporating three on one of top pinching and cools Y asamsa Icarriers from a common axis of rotation, vertically recinrocatlns mmbers sin traverse the cartons from under the hoods when position,carton feeding t nism when the hoods are lowered. said heating porting;said hoods. inverted v-ghaped carton top enga ing parts forming of saidhoods,

means engaging and lifting said members successively, meansfor feedingthe cartons under the hoods when the hoods are raked-,means for thecartons singly to'thf heating mechamechanism including one of saidrotarycarriers. a cover on said latter carrier, a plurality oichannel-like heating members on the cover' memher radiating from theaxis 61' rotation of its carrier; means automatically 'iiedlng theheated cartons successively to the pinching mechanism,

and cooling means with said pinthing mechanism;

HAROLD HOLMYARD B EASLEY.

